Signals transmitted between components of a radio communication network such as a base station and a mobile terminal may include different kinds of unwanted signal components which can disturb receiver performance. At cell center very low other cell interference is present. In such scenarios the inter chip/symbol interference introduced by the mobile channel's delay spread and the own cell's SCH (Synchronization Channel), such as P-SCH and S-SCH which are non-orthogonal to the desired OVSF (Orthogonal Variable Spreading Factor Code) spread signals are the main disturbances to the mobile receiver, for example the 3G Rel.99 receiver. In fact, only low delay spread channels having a strong first tap are expected for such high SINR (Signal to Interference and Noise) conditions such that the own cell's SCH 102 is the main disturbance to the mobile receiver.
When decoding the Enhanced Dedicated Channel Relative Grant Channel (E-RGCH), the non-orthogonal SCH introduces an additive bias which can lead to false decisions (false UPs/DOWNs, missed UPs/DOWNs). The magnitude of this bias depends on a number of PHY parameters, like SCH-power, PSC, P-SCH, S-SCH, E-RGCH/E-HICH OVSF code, E-RGCH/E-HICH signature sequence index. E-RGCH issues with the mentioned problem are known from field and lab tests.
Methods and devices employed in wireless communication networks constantly have to be improved. In particular, it may be desirable to improve the detection rate of the mobile receiver in situations as described above.